Continuously Manufactured Colored Metallic Products and Method of Manufacture of Such Products

ABSTRACT

Metallic tube, pipe and conduit are made in a continuous process that includes a zinc galvanization stage, a first passivation stage, a second passivation stage and a third passivation stage. A colorant is added to the tube, pipe or conduit during the continuous manufacturing process, and the colorant imparts the appearance of a color, such as red. The continuous movement of the tube, pipe or conduit is not halted during normal operation of the tube, pipe or conduit manufacturing and coloring process.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Non-provisional patentapplication Ser. No. 10/702,625, filed Nov. 6, 2003, which is anon-provisional of U.S. Provisional Application Ser. No. 60/455,933,filed Mar. 19, 2003, the entirety of which applications are incorporatedby reference herein.

FIELD OF INVENTION

The present invention relates to shaped metallic products such as steelpipe, tube or conduit made in a continuous manufacturing process thatincorporates coloration as a part of the continuous process and relatesto the method of manufacture of such metallic products.

BACKGROUND OF THE INVENTION

The present invention concerns shaped metallic products such as steelpipe, tube or conduit made in a continuous manufacturing process that,along with forming the metallic shaped product, adds color to the outersurface of the product. Metallic products such as tubes, pipes andconduit containing the appearance of color are extremely useful. Coloredtubes may be used to designate the purpose of the tube. For example,red-colored tube can be used to contain the electrical wires for firedetection and response systems; blue-colored tube can be used to containdrinking water or coolant; yellow-colored tube can be used to containand transport hot water. The addition of color to tube assists ininstallation and inspection of the tube and aids in easy identificationof tube that is used for a particular purpose.

Previously, manufacture of colored tube generally involved anon-continuous process. In previous processes, metal strip was formedinto tube in one process and then removed from the forming process.Color was then added to the tube in a different process. The colorationprocess occurred at a separate location and a separate time from thetube manufacturing process. The process for making the tube and theprocess for adding coloration, in the previous processes, were not partof the same continuous process. The use of separate processes for makingand adding color to tube has the drawbacks of decreasing the efficiencyand increasing the cost of the process of creating colored tube, andpreventing the colorant from being added to the tube as part of the tubemanufacturing process

In the current invention, the addition of color to the tube, pipe orconduit occurs in the same continuous process as that in which the tube,pipe or conduit is formed. The coloration process is part of thecontinuous manufacturing process. The tube, pipe or conduit does notcease moving and is not cut until after the coloration process in thecurrent invention. It is understood that while the word “tube” isfrequently used in this description, the description applies equally topipe, conduit and other metallic cylinders and columns as well as tube.In addition, while the specific examples mentioned in the preferredembodiments frequently refer to tube, the present invention includespipe, conduit, columns, cylinders, squares, rectangles, solids andnon-solid shapes (such as bars, beams, strips or other non-solid shapes)as well as tube.

The current invention has many benefits, including increased efficiency,decreased need for space for equipment, decreased labor and decreaseddifficulties involved in transferring formed and cut tube to acoloration station. The current invention provides for clearly visibletube systems, eases and saves time with installation and inspection, andassists with future upgrades and maintenance of tube systems. Thecurrent invention decreases the labor and material costs associated withpainting and creates greater system integrity.

BRIEF SUMMARY OF THE INVENTION

The present invention concerns shaped metallic products such as steeltube made in a continuous process in which the addition of color to thetube is a part of the continuous manufacturing process, and concerns theprocess for making such tube.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of one embodiment of the manufacturing processfor a metallic tube of the present invention.

FIG. 2 is a depiction of one embodiment of a finished metallic tube ofthe present invention, showing layers of the finished tube cut away.

Before the embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of the method, or arrangement of the components set forth inthe following description or illustrated in the drawings. The inventionis capable of other embodiments and of being practiced or being carriedout in various ways. Also, it is to be understood that the phraseologyand terminology used herein are for the purpose of description andshould not be regarded as limiting. The use of “including” and“comprising” and variations thereof is meant to encompass the itemslisted thereafter and equivalents thereof as well as additional itemsand equivalents thereof.

DETAILED DESCRIPTION OF THE INVENTION

The following paragraphs describe a few of the embodiments of thecurrent invention. In one embodiment, coiled steel is first obtainedfrom an external or internal source. The coiled steel typically is flat,cold rolled or hot rolled carbon steel. If the steel is hot rolled,typically it also is pickled to remove the scale, and then oiled andrecoiled. The coiled steel typically comes from one of numerous industrysources as flat rolls of steel weighing in excess of 1,000 lbs. Therolls typically are more than three feet wide upon receipt and containflat rolls of steel of approximately 2,000-3,500 feet in length.

The coiled steel is slit to obtain an appropriate width strip for theouter diameter or shape of the final product that will be manufactured.After being slit, the coiled steel is drawn off the roll and may beplaced into an accumulating station. The accumulating station connectsthe ends of flat strips of steel from different coils into a continuousflat strip.

The steel is then subject to a cleaning process to remove oil and othercontaminants. In the cleaning process, the steel is typically subjectedto a series of alkaline cleaners, high-pressure water and a squeegeeblow-off stage.

As shown in FIG. 1, in one embodiment of the invention, after beingcleaned the steel [10] begins a continuous manufacturing process. In thefirst stage [12] of the continuous process, the steel is formed. In thisstage, the steel is rolled or molded from its flat shape and into thedesired shape. Common desired shapes include tubes, squares, rectanglesand non-solid shapes.

After the steel is formed to the desired shape, it is subjected to awelding process which forms the steel into a continuous surface. If thedesired shape is a non-solid, the welding process is not used. Thewelding process typically creates a seam or weld [31] where the steelhas been connected to itself. Welding may be done by any common method,such as natural resistance, electrical resistance and high frequencywelding.

In some embodiments, before the steel reaches the welding point, a paintlance may be inserted into the interior of the steel. If the steel hasbeen formed into a tube, the paint lance is inserted inside the tube.The paint lance has a paint head that is down-stream from the insertionpoint of the lance. By the time the steel has progressed to the pointwhere the paint head is located, it has cooled sufficiently to allowpaint to be applied to the inner surface of the tube. The paint lancethen sprays paint, a coating, such as an antibacterial coating, acorrosion-resistance material or some other covering onto the interiorof the steel.

In some embodiments, after being welded, the outer surface of the steelis smoothed [32]. Again, if the desired shape is a non-solid and nowelding process is used, there is no need to employ a smoothing processand therefore this smoothing stage is avoided. Frequently, a roughenedor bumpy surface exists at the site of the weld after the weldingprocess. The smoothing process, which may involve wire brushing, removesthe rough or bumpy areas.

In some embodiments, after being smoothed, the steel is again cleaned[34] with a typical cleaner, such as an alkaline cleaner. The steel isthen subjected to an acid bath [36], which contains an acidic substancesuch as hydrochloric acid, which removes oxide from the steel surface.The steel is then rinsed [38] with a rinsing agent such as water andsubjected to pre-heating [50]. In the pre-heating stage, the temperatureof the steel is raised to the point that it may be subjected to rapidgalvanization.

After pre-heating, the steel is galvanized [52]. In some embodiments,the galvanization can be accomplished by any method that is standard forthe industry. One of these methods involves passing the steel through azinc pot. The zinc pot contains high levels of molten zinc. When thesteel passes through the molten zinc, some of the zinc may react withand adhere to the steel. The method by which such galvanization takesplace is well-understood in the industry.

After galvanization, the steel is subjected to a blow-off stage [54],which removes excess zinc through blown air, vibration or contactremoval. The steel then passes through a liquid quenching stage [56] insome embodiments, which lowers the temperature of the steel and sets thezinc into the steel. Common quenching methods include passing the tubethrough a bath of temperate water. After being quenched, the steel issized [70]. In this stage the steel is subjected to sizers, such asrollers and molders, which form the steel into the exact desired outerdiameter or shape.

Different outer diameters and shapes are used for differentapplications. Tube with an outer diameter of a maximum of 1.740, 1.510,1.163, 0.922 or 0.706 inches is useful for applications that benefitfrom tube with a smaller diameter, such as carrying small amounts ofelectrical wire, water or compressed air. Tube with an outer diameter ofa minimum of 2.197, 2.875, 3.5, 4.0 or 4.5 inches is useful forapplications that benefit from tube with a larger diameter, such ascarrying larger amounts of electrical wire, water or compressed air.Different gauges of tube are involved in the present invention. In oneembodiment, the final manufactured tube has a gauge approximatelybetween 8 and 18.

In the embodiment of the invention shown in FIG. 1, the steel is thensubjected to passivation. In the passivation stage [72], a barrier isbonded (through physical and/or chemical bonding) on the outer zincsurface. Passivation can be accomplished through a reactive process, anon-reactive process or a combination of reactive and non-reactiveprocessing. The passivation barrier may decrease interactions betweenoutside moisture or air and the zinc layer or the underlying steel andmay form a coating. The barrier may limit white rust or othercontamination occurring on the surface of the zinc. The barrier also canprovide corrosion resistance. One method of passivating the zinc is topass the zinc-coated steel through a bath that includes hexavalentchromium. Other passivation methods, including the use of non-chromiumcoatings, also can be used.

In the embodiment shown in FIG. 1, after the first passivation stage,the steel may be subjected to a second passivation stage [74]. In thesecond passivation stage, a second barrier is placed over and bonded(through physical and/or chemical bonding) to the first barrier. Thesecond passivation stage can employ reactive processes, non-reactiveprocesses or a combination of reactive and non-reactive processes. Thesecond passivation barrier may form a coating and may assist withcorrosion resistance and inhibit air and moisture from interacting withthe first barrier, the zinc layer and/or the steel.

In the embodiment shown in FIG. 1, after the second passivation stage,the steel may be subjected to a third passivation stage [76]. In thethird passivation stage, a third barrier is placed over and bonded(through physical and/or chemical bonding) to the second barrier. Thepassivating substance used in the third passivation stage may mix orintermingle with the passivating substance in the second passivationstage prior to either substance fully setting or drying. The resultingbonds that are formed create increased interconnectivity between thesecond and third passivation stage. In other embodiments (e.g., wherethe distance between the second passivation stage and the thirdpassivation stage is large or where the second passivation substance(s)dries quickly), the third passivation substance does not mix orintermingle with the substance over which it is applied.

The third passivation stage can employ reactive processes, non-reactiveprocesses or a combination of reactive and non-reactive processes. Thethird passivation barrier may form a coating and may assist withcorrosion resistance and may inhibit air and moisture from interactingwith the second barrier, the first barrier, the zinc layer and/or thesteel. Additional passivation stages beyond the third passivation stage,placing additional barriers over the metallic substrate, also may beused.

In one embodiment, the method used for the passivation stage(s) involvespassing the tube through a bath of the passivating substance. Anotherembodiment involves a flood and wipe method that involves passing thesteel tube through a bath that includes a lacquer or other passivatingsubstance, and excess passivating substance is then wiped from the tubeas it nears the end of the passivation stage. In another embodiment, themethod used in the passivation stage(s) involves a vacuum coating methodthat involves passing the steel through a vacuum chamber and sprayingthe passivating substance, such as a lacquer, on the steel. Excesssubstance is then vacuumed off the exterior of the tube. Additionalembodiments of the present invention involve application of passivationsubstances through other methods, such as conventional spray,electrostatic spray, fluidized bed, and a combination of two or more ofthese methods.

The passivation substances and passivation barriers may form completebarriers or may form only partial barriers. In some embodiments, thepassivation substances are applied as uniform coatings that fully coatthe underlying layer or tube. In other embodiments, the passivationsubstances are applied as patterns and only partially coat theunderlying layer or tube. In these later embodiments, the partialcoating of the passivation substance does not provide a uniform barrierbetween the outside air and the underlying layers and tube, and theability of the substance to assist with corrosion resistance and inhibitair and moisture from interacting with the underlying layers and steelmay be further limited or eliminated altogether.

In one embodiment, the method used for application of the passivationsubstance(s), especially in the third passivation stage, involvesspraying and curing or drying. The steel tube passes through a spraystation in which several nozzles spray the passivation substance(s), ina liquid form, onto the exterior of the pipe and underlying coatings.The nozzles are easily adjustable. The size of the particle that leavesthe nozzle can be adjusted by adjusting the size of the nozzle orificethrough which the passivation substance passes. The volume of the flowof material through the nozzle also can be adjusted. In someembodiments, a nozzle orifice size of between approximately 0.01 and0.02 inches is preferred and a nozzle orifice of approximately 0.015inches more preferred. A decrease in the size of the particle that issprayed on the tube makes the coating on the tube more even. Throughthis spraying method, a uniform amount of the passivation substance(s)is applied to the exterior.

In another embodiment, the method used for application of thepassivation substance(s) especially in the third passivation stage,involves a vacuum coating method. In this method, the steel tube passesthrough a vacuum chamber. The passivating substance is sprayed onto thesteel while it is in the chamber. Excess substance is then vacuumed offthe exterior of the tube. Through the method of vacuum coating, asubstantially uniform amount of passivation substance is applied to theexterior of the tube.

Numerous other passivation methods are common in the industry for thepassivation stage(s). Each of the passivation methods described hereincan be used for the first, second, third, or subsequent passivationstages.

Substances involved in the passivation process include urethanes,acrylic compounds or epoxies, which are often contained in lacquers orpowders, all of which are commonly available in the market. Thesepassivation substances may be solids, water based or solvent based, andmay be cured in standard manners, including ultra violet light,induction, infrared, conventional, air and electron beam curing. Thesepassivation substances also may contain polymer resins, organics,chromium or solvents. Where the passivation substances contain organics,the coatings they form may be referred to as organic coatings. Thesepassivation substances can contain materials such as chromium, sec butylalcohol, propylene glycol, propylene glycol n-propyl ether, 2-butoxyethanol, triethylamine and other materials. The passivation substancesform a bond, physical or chemical, with the layer beneath them, and mayor may not be involved in chemical reactions with the underlyinglayer(s), the underlying zinc or the underlying metal. In someembodiments the passivation substances may contain no less than 60%water. In some embodiments the passivation substances may contain nomore than 20% solids. The level of solids and/or level of water in thepassivation substances can assist the ease of the application of thepassivation substances and can promote uniform coating.

In one embodiment, the passivation substance used in one or more stagesincludes a colorant. This colorant may be any substance that imparts theappearance of a color, shade, value or hue to the outer surface of themetal, such as a pigment, powder, liquid, ink or identifying lacquer.Numerous colors can be used with the colorant, including red, green,yellow, blue, orange, purple, brown, white, black and other colors. Thiscolorant remains with the tube or other shape after the continuousmanufacturing process is completed.

Care must be taken when using a flood and wipe method to apply colorant.This method can cause streaking of the color and make the pipe visuallyunappealing if not closely monitored. In the flood and wipe method, thewipe cloth may need to be changed frequently (every 10 minutes) to avoidstreaking. Applying colorant as part of a spraying process, as describedabove, assists in eliminating such streaking. Applying colorant in thespraying process also applies a thinner color than is applied in thevacuum coating process. This thinner color is more easily applied in amanner that keeps the color somewhat transparent.

The passivation stages and passivation substances previously describedeach are optional. In one embodiment of the present invention, three ormore passivation stages are used. In another embodiment, only onepassivation stage is used. In another embodiment, there is nopassivation stage.

The present invention also encompasses colorant being applied to thetube or other shape at one or more of several different phases in thecontinuous manufacturing process. In one embodiment, colorant is addedin the third passivation stage. If an earlier passivation substanceincludes chromium, the colorant added to the third passivation stage mayneed to be compatible with chromium. In other embodiments, the colorantis added in the first or second passivation stage. In anotherembodiment, the colorant is added in the sole passivation stage. Inanother embodiment, the colorant is added as part of the galvanizationstage. Colorant added in the galvanization stage must maintain itsintegrity at the temperature of the galvanization stage. In otherembodiments, color is added before the first passivation stage, afterthe last passivation stage, or in several passivation and/ornon-passivation stages.

One method of adding a colorant to the metal during the galvanizationstage involves including a colorant in the quench material that isapplied to the tube after it leaves the galvanization stage. Suchcolorants are readily available and include pigments, powders, liquids,inks or identifying lacquers. The quench material used may be water orsome other solvent (organic or inorganic), and the colorant is combinedwith this material prior to the quenching of the steel. The quenchmaterial, including the colorant, forms a bond with the galvanized tubeand imparts the appearance of color to the tube.

In another embodiment of the present invention, colorant is added beforethe first passivation stage or after the final passivation stage. Priorto the first passivation stage or after the final passivation stage, anadditional substance, such as a coating, paint, resin, powder orlacquer, is applied to all or a portion of the tube. This substancecontains a colorant, which imparts the appearance of color to the tube.This substance can be applied to the tube through numerous well-knownprocesses such as spray (e.g., electrostatic spray or conventionalspray), fluidized bed, powder or vacuum coating. The colorant may beapplied to the entire tube, or may be applied to a portion of the tubein a pattern, such as a stripe, spiral, text, dots or other pattern.

After leaving the third passivation stage, in some embodiments, the tubeenters a drying stage [80]. In the drying stage the final passivationsubstance is cured and/or dried to the point that the tube can betouched by a bounce limiter or other device after leaving the dryingstage without rubbing off a portion of the passivation substance.

In some embodiments the drying stage can take the form of an inductionbox [82] followed by a drying tunnel [84]. The induction box [82] mayconsist of a pipe of non-magnetic material that is approximately 3-7feet long and wider than the tube being manufactured. A coil is wrappedaround the pipe and a current is passed through the coil creating amagnetic field and a heating area for objects that pass within the pipe.The tube then passes through the pipe and is heated. An air source alsois connected to the pipe to pass air through the heating area. In someembodiments the air moves at a rate of approximately 1500-2500 cfm. Theair is generally approximately 20-50 degrees Fahrenheit warmer thanambient air. Tube moving at a rate of 600 ft./min. passes through aninduction box with a length of approximately 3-7 feet in approximately0.3-0.7 seconds.

In some embodiments the induction box is followed by a dry tunnel [84].The dry tunnel [84] is a pipe that that is wider than the tube beingmanufactured and is approximately 6-10 feet long. An air source isconnected to this pipe, which passes air through the pipe at a rate ofapproximately 1500-2500 cfm. The air is generally approximately 20-50degrees Fahrenheit warmer than ambient air. The tube being manufacturedpasses inside this pipe and is contacted by the blowing air. Tube movingat a rate of 600 ft./min. passes through a dry tunnel with a length ofapproximately 6-10 feet in approximately 0.6-1 second. In someembodiments, when the tube leaves the dry tunnel, the third passivationsubstance has dried to the point that the tube can be touched withoutmarring the surface. In these embodiments, the third passivationsubstance dries or cures within approximately between 0.9 and 1.7seconds after it is applied to the tube.

In some embodiments, the steel may be subject to additional heating,cooling and/or drying. In some embodiments, bounce limiters [86] areinstalled after the drying stage(s). At the end of the manufacturingprocess, the steel is cut to the desired length with a blade or othercutting device [102]. The blade may include a sharp device that swingsthrough the tube at desired intervals. The cutting process may cause thesteel to bounce somewhat. The cutting blade may cause the steel to slowits forwarded advancement slightly when the steel is cut. When theforward advancement is slowed, the steel bounces in a vertical directionto maintain its continuous advancement. This bouncing can havedeleterious effects on the outer surfaces of the steel and cannegatively impact the continuous manufacturing process. To limit thisbouncing, bounce limiters [86] are installed in the continuousmanufacturing process to be available to contact the steel after it hasbeen dried and before the cutting stage.

Bounce limiters in some embodiments diminish the amplitude of bouncingof the tube caused by cutting and limit the propagation of large bounceamplitudes backward along the continuous manufacturing process. In someembodiments bounce limiters can include bounce rolls that are made ofpolyethylene, polypropylene, other plastic, metal or other formativesubstance. Bounce limiters can incorporate springs or other shockmechanisms that will assist in at least partially absorbing anddissipating the bounce of the tube. These springs or shock mechanismsare optional and the bounce limiters can function without them in someembodiments. The bounce limiters may be connected to a stationarymaterial that does not move in a vertical direction.

Bounce limiters can be placed underneath the tube to limit the tube fromtraveling downward from its manufacturing path. Bounce limiters also canbe placed above the tube to limit the tube from altering itsmanufacturing path and moving upward. In one embodiment, bounce limitershave no spring mechanism and take the form of a pair of cylindricalrolls that roll with the tube when the tube is in contact with them andprevent the tube from moving in a downward direction. Bounce limiterpairs may be horizontally staggered so that one bounce limiter isfurther downstream in the manufacturing process than the other bouncelimiter of the pair. Due to the dryness of the tube after the dryingstage(s) the bounce limiters have very limited effect on the appearanceor functionality of the outer coating on the tube.

After passing through the bounce limiters, the steel is cut in thecutting stage [100] that includes a blade or other cutting device [102].The blade may be a metal object that swings through the tube veryquickly. The blade also may be incorporated into a mechanism thatbriefly attaches to the tube prior to cutting, travels with the tubeduring cutting and then detaches from the tube. The blade may include asharp device that swings through the tube at desired intervals.

The present invention imparts color to galvanized tube in someembodiments. Due to its galvanized nature, the tube may be rippled withmarkings referred to in the industry as galvanization ripples, air ringsor water quench rings. The present invention imparts color to the tuberegardless of this rippling. The present invention also imparts color tothe tube regardless of whether the tube has been buffed or polished orotherwise smoothed.

During the continuous manufacturing process, in one embodiment, thesteel moves at a substantially constant rate of speed. This rate ispreferably more than one hundred feet per minute, more preferably morethan three hundred feet per minute, even more preferably more than sixhundred feet per minute, and most preferably more than one thousand feetper minute. The steel moves from the forming stage through the finalpassivating stage and to the cutting stage in a continuous process. Thesteel is not stopped at any normal operating time, but continuouslymoves through each stage of the entire process.

An additional embodiment of the present invention involves the use ofpre-galvanized steel in the continuous manufacturing process. In thisembodiment, rather than beginning the process with cold or hot rolledsteel that has been cut and cleaned, but not galvanized, the processbegins with steel that already has been subject to galvanization. Inthis embodiment, the steel is pre-galvanized before it begins thecontinuous manufacturing process.

In one embodiment of the present invention, a flat strip ofpre-galvanized steel is subjected to the continuous forming process andthe welding process as described above. After being welded, the tube orother solid shape of pre-galvanized steel will have an area at the weldin which the galvanization has been removed. The zinc galvanization isreplaced on this area through numerous methods well known in the art,such as by arc flash or vaporization of zinc wire at the site of theweld. Through this process, additional zinc is placed or sprayed ontothe weld area, thereby replacing the zinc that was removed during thewelding process. If the desired end shape is a non-solid, the weldingand zinc galvanization replacement stages are not used.

After the galvanization replacement stage, this tube or other shape maygo through one or more of the stages described above, including thepassivation stages. A colorant also may be added to this tube or othershape through the methods described above.

In another embodiment of the present invention, the steel is nevergalvanized. The galvanization stage described above may be replaced witha galvalum or galvanealing stage. Galvalum and galvanealing processesare well known in the art. The galvanization stage also may be replacedwith a process that hardens and strengthens the metal and lowers itsductility.

FIG. 2 shows one embodiment of the present invention with layers ofsteel tube cut away. The first and innermost layer is the steel itself[110]. The next layer is a zinc galvanization layer [112]. The nextlayer is a first passivation layer [114]. A second passivation layer[116] also may be included over the first passivation layer. A thirdpassivation layer [118] also may be included over the second passivationlayer. The first, second and third passivation layers may contain any orall of the passivation substances described above and/or chromium.

The processes described above may be used to create different types oftube, including Electrical Metallic Tubing, Intermediate Metal Conduitand tube that meets the specifications set forth by standardizationorganizations, such as the Underwriters Laboratories, Inc. and AmericanNational Standards Institute, including UL 797, UL 1242, ANSI C80.3 andANSI C80.6, each of which is enclosed and incorporated by reference inthis application. In a preferred embodiment, the process described aboveis used to make Electrical Metallic Tubing.

In one embodiment, tube made from the process described above may beused to enclose and protect electrical wire. Such electrical wire isplaced within the tube subsequent to manufacture of the tube andinstalled with a corresponding electrical system. This tube also can beused to house other substances such as liquids, water for sprinklersystems or gases.

After the tube has been manufactured, it may be installed. Differentcolors of the tube can be installed for different applications. In oneembodiment, to install this tube, colored tube made from the continuousprocess described herein is placed in or near a building. Electricalwires that are part of or related to the building's fire alarm detectionand/or response systems are then placed within the tube. These wires maybe connected to the building's central computing system or systems. Onemethod of placing the wires in the tube is to blow a lead string throughthe tube. This string is attached to the wires and by pulling the stringfrom one end of the tube, the wires are pulled through the tube. Othermethods of placing the wires in the tube are well understood in theindustry.

The electrical wires within the colored tube are easily locatable inthis embodiment. For fire alarm detection or response systems, tube witha red color can be used. By locating the red-colored tubes, one haslocated the electrical wires for the fire alarm detection and responsesystem.

This same installation method can be used for other applications withtube containing different colors. Tube made using the process describedherein and containing another color, such as green or yellow, may beinstalled in or near a building. Electrical wire for other applications,such as computing applications, security, lighting, motion tracking,ventilation, air conditioning, and heating is then placed within thetube and may be connected to the building's central computing or datacollection system.

In this manner, the wire for these applications can be easily located intimes of need by locating tube with the appropriate color. Additionalsystems, such as sprinkler systems or gas systems containing gases suchas oxygen or compressed air, can be incorporated into tube madeaccording to the invention described herein and containing a differentcolor, such as blue, orange, or other color, and that has been installedin or near a building.

A particular building may contain two or more separately colored tubes.Each separately colored tube contains wires or other substances fordistinct applications. For example, a particular building may containred tube for fire detection and treatment wires and substances, greentube for computing wires, yellow tube for electrical wires related tolighting, blue tube for a water or a sprinkler system, and orange tubefor motion tracking devices. The wires or other substances in one ormore of the tubes may be connected to the building's central computingsystem or systems. This central system may consist of one or morecomputers or computing devices. This central system may be used tocollect the information provided by and coordinate the activity of thesubstances in each separately colored tube.

While the invention has been described with respect to specific examplesand embodiments including presently preferred modes of carrying out theinvention, those skilled in the art will appreciate that there arenumerous variations and permutations of the above described substancesand methods that fall within the spirit and scope of the invention.

1. A method for imparting a colorant to a metallic surface during acontinuous manufacturing process, comprising: moving a metal tube in acontinuous manufacturing process; applying a coating to an inner surfaceof the metal tube; galvanizing an outer surface of the metal tube;applying a chromate coating over the galvanized surface, the chromatecoating including a colorant; and applying a clear organic polymercoating over the chromate coating.
 2. The method of claim 1, wherein thecolorant is a liquid colorant.
 3. The method of claim 1, wherein themovement of a steel tube in the continuous manufacturing process has arate of speed of more than about six hundred feet per minute.
 4. Themethod of claim 3, wherein the movement of a steel tube in thecontinuous manufacturing process has a rate of speed of more than aboutone thousand feet per minute.
 5. The method of claim 1, furthercomprising curing the colorant using ultraviolet light curing.
 6. Themethod of claim 1, wherein the coating is a paint.
 7. The method ofclaim 1, wherein the coating is a corrosion resistant coating.
 8. Themethod of claim 1, wherein the coating is an antibacterial coating.
 9. Amethod for imparting a colorant to a metallic surface during acontinuous manufacturing process, comprising: moving a metal tube in acontinuous manufacturing process; applying a corrosion resistant coatingto an inner surface of the metal tube; galvanizing an outer surface ofthe metal tube; applying a first passivation layer over the galvanizedouter surface, the first passivation layer including chromium and acolorant; and applying a clear organic polymer coating over the firstpassivation layer.
 10. The method of claim 9, wherein the colorant isselected from the list consisting of pigment, powder, liquid, ink andidentifying lacquer.
 11. The method of claim 9, wherein the movement ofa steel tube in the continuous manufacturing process has a rate of speedof more than about one thousand feet per minute.
 12. The method of claim9, further comprising curing the colorant using ultraviolet lightcuring.
 13. The method of claim 9, wherein the continuous manufacturingprocess occurs at a substantially constant rate of speed.
 14. The methodof claim 9, wherein the colorant comprises a pigment, a powder, a liquidink, or an identifying lacquer.
 15. A method for imparting a colorant toa metallic surface during a continuous manufacturing process,comprising: moving a metallic tube in a continuous manufacturingprocess; applying a coating to an inner surface of the metallic tube;galvanizing an outer surface of the metallic tube; applying first andsecond passivation layers over the galvanized outer surface; andproviding a colorant on or in the first passivation layer; wherein thefirst passivation layer includes chromate, and the second passivationlayer comprises a clear organic polymer coating.
 16. The method of claim15, wherein a third passivation layer is applied over the secondpassivation layer before the second and third passivation layers set orfully dry so that said second and third passivation layers intermingleto provide increased interconnectivity there between.
 17. The method ofclaim 16, wherein at least one of the first, second and thirdpassivation layers contains said colorant, and said passivation layercontaining said colorant is applied as a pattern.
 18. The method ofclaim 15, wherein the coating is an antibacterial coating.
 19. Themethod of claim 15, wherein the coating is a corrosion resistantcoating.
 20. The method of claim 15, wherein the colorant comprises apigment, a powder, a liquid ink, or an identifying lacquer.